Man's preoccupation with invisibility goes back thousands of years. From voyeurism to self-defense, our rationale for disappearance varies almost as much as the methods we've attempted to employ in attaining it.

Now an Australian company has teamed with scientists to create the world's first "invisible" wetsuit, using patterns to blend with the surrounding ocean and hoping it will make surfers harder for sharks to see. While it's unknown if this will work — no one is sure just why sharks attack humans — this is far from our first attempt at becoming unseen. Here's a look at a few other projects:

Using "Augmented Reality", a Japanese firm has made a cloak made from "Retro-Reflective Projection Technology". Basically, a camera takes a picture of the area behind you, then processes it through a computer and projects the scene back onto you. Unfortunately, the process is complicated, and doesn't really allow for a great deal of mobility.

Deep in the heart of Texas, scientists have invented what they're calling a "mantle cloak", which disturbs light waves and makes objects invisible to microwave detectors — though as of yet still visible to the human eye. It's claimed to be expandable to work on the ranges of light we see, but would only work on objects thinner than a human hair, which, while probably cool to scientists, doesn't have much in the way of a "wow" factor.

A defense company has a system that can hide a tank — but only in the infrared spectrum. ADAPTIV, as it is called, uses panels placed around the tank that can "paint" with individual heat signatures, changing the shape of the tank to that of a car, for example, or its markings to a friendly logo, but only when viewed with thermal imaging such as night-vision goggles.

Using a "clear, hexagonal device" of normal materials — no special magic here — that bend light around the object desired to be hidden, Japanese scientists managed to obscure both a cat and a goldfish, and the technology garnered the Sir Isaac Newton medal for its creator, a British physicist. Unfortunately, while hiding its contents, the device remains visible. Which sort of defeats the point.

In what may be the craziest one yet, scientists at Purdue University have managed to use lasers to separate light waves and then bring them back together, effectively creating a "time hole" in which data streams, and they hope one day entire events will simply disappear. It's a bit complicated, and unfortunately might just work a little too well: the experiment they performed "erased itself from history".

Okay, so maybe we're not quite at the Harry Potter stage of things just yet, but it's only a matter of time. Until then, there's always the old standby.